1. Field of the Invention
This invention relates to a read-while-write magnetic head assembly adapted for use with a recording medium which is transported thereacross and more particularly to a transducing head assembly formed of two thin film transducing head sub-assemblies joined together with a feed-through shield located therebetween. One transducing head sub-assembly may consist of one or more magnetoresistive thin film transducers deposited onto a substrate.
2. Description of the Prior Art
The use of thin film transducers as part of a transducing head assembly and the method of fabricating the same are well known in the art. One method of fabricating a thin film magnetic head assembly having glass bonded thin film transducers is disclosed in U.S. Pat. No. 4,143,458 entitled Method Of Making a Thin Film Magnetic Head Assembly by George W. Gibson assigned to the Assignee of the present application.
A magnetic assembly having glass bonded thin film transducers is disclosed in U.S. Pat. No. 4,191,983 entitled Thin Film Magnetic Head Assembly Having A Thin Film Magnetic Transducer Encapsulated In Insulation Bonding Material by George W. Gibson asigned to the Assignee of the present application.
Typically magnetic head assemblies formed of thin film magnetic transducers are utilized in apparatus for recording and reproducing information onto and from a magnetic medium. The magnetic recording and reproducing apparatus may be a magnetic disc or magnetic tape. In magnetic disc recording and reproducing apparatus, the magnetic disc is rotated relative to the magnetic head assembly at a constant speed. Typically, the reading and recording of information onto and from the rotating magnetic medium is accomplished by using inductive thin film magnetic transducers as the transducers forming the magnetic head assembly. In certain of the magnetic disc apparatus, the magnetic head assembly includes a slider which enables the magnetic head assembly to fly on a thin film air bearing. The thin film air bearing provides non-contact magnetic transducing acting between the magnetic head assembly, which may contain one or more magnetic transducing heads, and the rotating magnetic medium.
In magnetic tape recording and reproducing apparatus, the magnetic head assembly is oriented relative to the magnetic tape such that the magnetic tape is in contact with and is transported across the magnetic tape head assembly. During operation, the magnetic tape is transported across and contacts the magnetic head assembly resulting in the magnetic tape abrading the medium contacting surface of the magnetic head assembly. This has the attended effect of wearing both the magnetic tape and magnetic head assembly, which directly determine both tape life and head life.
It is likewise known in the art to utilize an inductive magnetic transducer as the "write" transducer and a magnetoresistive transducer as the "read" transducer in a magnetic head assembly, such as, for example, in a magnetic tape head assembly. In a magnetic tape head assembly, the magnetoresistive transducer produces electrical signals from the information recorded on a magnetic medium and the magnitude of the so produced electrical signal is independent of any variations in the speed of the magnetic tape being transported thereacross. However, a magnetoresistive transducer is sensitive to magnetic fields produced by an inductive magnetic transducer. As such, the magnetoresistive transducer sub-assembly is typically shielded from the inductive magnetic assembly to eliminate feed-through therebetween.
One known process for fabricating a read-while-write magnetic tape head assembly using an inductive write transducer and a magnetoresistive read transducer is disclosed in U.S. Pat. No. 440,44,392. In the method disclosed in U.S. Pat. No. 360/113 124, the active read and write elements are deposited on ferrite half-yokes attached to titanium or baria titania ceramic end pieces. A center section, formed of a sandwich of silver-copper shielding material between two ferrite sheets having glass filled slots, is placed between the read and write transducers with the write windings between pairs of the glass filled slots. The magnetoresistive elements are positioned in contact with the opposite surface of the center shield. The glass filled slots on each side of the write elements define the track edge. The titanium or the baria titania ceramic end pieces, having the inductive elements and magnetoresistive elements formed thereon, are assembled with the center section therebetween and joined together in a manner such that a vise-like action holds the magnetic tape head assembly together.
It is also known in the art to mount a magnetic disc head assembly onto magnetic head sliders to form a magnetic head slider assembly. Typically, magnetic head slider assemblies are utilized to fly the magnetic head assembly supported thereby on an air bearing relative to a rotating magnetic disc. With the advent of thin film magnetic transducers, the physical size of the transducing element is extremely small. This has necessitated a reduction in size of the slider elements which, in turn, has caused an increase in the difficulty of fabricating the smaller slider elements. As a result thereof, new compositions of material have been developed which are resistent to breakage, have improved machining properties and good wear characteristics. One such magnetic head slider assembly is disclosed in U.S. Pat. No. 4,251,841 wherein the slider element is formed of a mixture of Aluminum Oxide (Al.sub.2 O.sub.3) and Titanium Carbide (TiC) in certain ratios and of compositions having certain grain sizes, all as disclosed in the U.S. Pat. No. 4,251,841.